Methods and image processing devices for encoding and decoding private data

ABSTRACT

Methods and image processing devices for encoding and decoding private data are proposed. The method for encoding private data includes to receive an original video frame, mask at least one private area in the original video frame to generate a protected video frame, generate a first encoded frame by encoding the protected video frame, and generate at least one output bitstream for streaming or storage according to the first encoded frame. The method for decoding private data includes to receive at least one input video bitstream to obtain a first encoded bitstream and a second encoded bitstream, decode the first encoded bitstream to generate a protected video frame including image data associated with at least one private area, and output the protected video frame to a display queue such that the at least one private area is displayed.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of U.S. provisionalapplications Ser. No. 63/027,962, filed on May 21, 2020. The entirety ofthe above-mentioned patent application is hereby incorporated byreference herein and made a part of this specification.

TECHNICAL FIELD

The disclosure relates to techniques for encoding and decoding privatedata.

BACKGROUND

Google has been using a technology to blur faces in its Street Viewfeature in an attempt to protect the privacy of individuals asillustrated in a schematic diagram of a street view image 100 in FIG. 1,where a face F of an in individual H is anonymized. In terms of faceblur in surveillance network video recorders (NVR), two conventionalapproaches are presented as follows.

In the conventional first approach, as illustrated in FIG. 2A, anoriginal video captured by a surveillance camera 210A would beduplicated, and all facial areas in the duplicated video would bedetected and blurred to generate a protected video. Image data of boththe original video and the protected video would be transmitted, forexample, to a central control room 220A. A security guard would performsecurity monitor duties on the protected video. The original video wouldbe encrypted, and a police officer or any other authorized person wouldperform investigation on the original video by using a decryption key ifany criminal behaviour is found in the protected video. In the firstconventional approach, double memory spaces are required for storage anddouble network bandwidth are required for streaming.

In the second conventional approach, as illustrated in FIG. 2B, anoriginal video captured by a surveillance camera 220A and private areadata such as coordinates of facial areas determined from the originalvideo would be transmitted to a central control room 220B. The facialareas in the original video would be blurred by a computer system togenerate a masked video according to the private area data in thecentral control room. An operator would perform security monitor dutieson the masked video. The original video would be encrypted as well, anda police officer or any other authorized person would performinvestigation on the original video by using a decryption key if anycriminal behaviour is found in the masked video.

However, security issues have not been addressed adequately in bothaforesaid approaches since the private data is secured by the NVR at thesystem level. The operator may access the original unprotected video ifthe decryption key has been leaked or video file has been transferred toother system.

SUMMARY OF THE DISCLOSURE

Methods and image processing devices for encoding and decoding privatedata are proposed.

According to one of the exemplary embodiments, the method for encodingprivate data includes the following steps. An original video frame isreceived. At least one private area in the original frame is masked togenerate a protected video frame. A first encoded frame is generated byencoding the protected video frame. At least one output bitstream forstreaming or storage is generated according to the first encoded frame.

According to one of the exemplary embodiments, the image processingdevice includes a receiving circuit, a masking circuit, an encodingcircuit, and an output circuit. The receiving circuit is configured toreceive an original video frame. The masking circuit is configured tomask at least one private area in the original video frame to generate aprotected video frame. The encoding circuit is configured to generate afirst encoded frame by encoding the protected video frame. The outputcircuit is configured to generate at least one output bitstream forstreaming or storage according to the first encoded frame.

According to one of the exemplary embodiments, the image processingdevice includes a processor. The processor is configured to receive anoriginal video frame, mask at least one private area in the originalvideo frame to generate a protected video frame, generate a firstencoded frame by encoding the protected video frame, and generate atleast one output bitstream for streaming or storage according to thefirst encoded frame.

According to one of the exemplary embodiments, the method for decodingprivate data includes the following steps. At least one input videobitstream is received to obtain a first encoded bitstream and a secondencoded bitstream. The first encoded bitstream is decoded to generate aprotected video frame including image data associated with at least oneprivate area. The protected video frame is outputted to a display queuesuch that the at least one private area is displayed.

According to one of the exemplary embodiments, the image processingdevice includes a receiving circuit, a decoding circuit, and an outputcircuit. The receiving circuit is configured to receive at least oneinput video bitstream to obtain a first encoded bitstream and a secondencoded bitstream. The decoding circuit is configured to decode thefirst encoded bitstream to generate a protected video frame includingimage data of at least one private area. The output circuit isconfigured to output the protected video frame to a display queue suchthat the at least one private area is displayed.

According to one of the exemplary embodiments, the image processingdevice includes a processor. The processor is configured to receive atleast one input video bitstream to obtain a first encoded bitstream anda second encoded bitstream, decode the first encoded bitstream togenerate a protected video frame including image data of at least oneprivate area, and output the protected video frame to a display queuesuch that the at least one private area is displayed.

In order to make the aforementioned features and advantages of thedisclosure comprehensible, preferred embodiments accompanied withfigures are described in detail below. It is to be understood that boththe foregoing general description and the following detailed descriptionare exemplary, and are intended to provide further explanation of thedisclosure as claimed.

It should be understood, however, that this summary may not contain allof the aspect and embodiments of the disclosure and is therefore notmeant to be limiting or restrictive in any manner. Also, the disclosurewould include improvements and modifications which are obvious to oneskilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments of thedisclosure and, together with the description, serve to explain theprinciples of the disclosure.

FIG. 1 illustrates a schematic diagram of a street view image with faceblur in accordance with an existing technology.

FIG. 2A illustrates a schematic diagram of a first conventional approachfor face blur in NVR.

FIG. 2B illustrates a schematic diagram of a second conventionalapproach for face blur in NVR.

FIG. 3A and FIG. 3B illustrate schematic diagrams of proposed imageprocessing devices in accordance with one of the exemplary embodimentsof the disclosure.

FIG. 4 illustrates a flowchart of a proposed method for encoding privatedata in accordance with one of the exemplary embodiments of thedisclosure.

FIG. 5 illustrates a functional diagram of a proposed method forencoding private data in accordance with one of the exemplaryembodiments of the disclosure.

FIG. 6A and FIG. 6B illustrate schematic diagrams of proposed imageprocessing devices in accordance with one of the exemplary embodimentsof the disclosure.

FIG. 7 illustrates a flowchart of a proposed method for decoding privatedata in accordance with one of the exemplary embodiments of thedisclosure.

FIG. 8A illustrates a functional diagram of a proposed method fordecoding private data in accordance with one of the exemplaryembodiments of the disclosure.

FIG. 8B illustrates a schematic diagram of private data and protecteddata for playback in accordance with one of exemplary embodiments of thedisclosure.

To make the above features and advantages of the application morecomprehensible, several embodiments accompanied with drawings aredescribed in detail as follows.

DESCRIPTION OF THE EMBODIMENTS

Some embodiments of the disclosure will now be described more fullyhereinafter with reference to the accompanying drawings, in which some,but not all embodiments of the application are shown. Indeed, variousembodiments of the disclosure may be embodied in many different formsand should not be construed as limited to the embodiments set forthherein; rather, these embodiments are provided so that this disclosurewill satisfy applicable legal requirements. Like reference numeralsrefer to like elements throughout.

FIG. 3A and FIG. 3B illustrate schematic diagrams of proposed imageprocessing devices in accordance with one of the exemplary embodimentsof the disclosure. Note that both image processing devices proposed inFIG. 3A and FIG. 3B would be used for encoding private data. Allcomponents of the image processing devices and their configurations arefirst introduced in FIG. 3A and FIG. 3B. The functionalities of thecomponents are disclosed in more detail in conjunction with FIG. 4.

Referring to FIG. 3A, an image processing device 300A would beimplemented as an integrated circuit (IC) including a receiving circuit310, a masking circuit 320, an encoding circuit 330, and an outputcircuit 340, where the masking circuit 320 is coupled to the receivingcircuit 310, the encoding circuit 330 is coupled to the masking circuit320, and the output circuit 340 is coupled to the encoding circuit 330.Note that in one of exemplary embodiments, an encrypting circuit 335coupled between the encoding circuit 330 and the output circuit 340 maybe optionally included in the image processing device 300A.

Referring to FIG. 3B, an image processing device 300B would be anelectronic system or a computer system that includes a processor 350.The processor 350 may be may be one or more of a North Bridge, a SouthBridge, a field programmable array (FPGA), a programmable logic device(PLD), an application specific integrated circuit (ASIC), other similardevices, or a combination thereof. The processor may also be a centralprocessing unit (CPU), a programmable general purpose or special purposemicroprocessor, a digital signal processor (DSP), a graphics processingunit (GPU), other similar devices, or a combination thereof.

FIG. 4 illustrates a flowchart of a proposed method for encoding privatedata in accordance with one of the exemplary embodiments of thedisclosure. The steps of FIG. 4 could be implemented by the proposedimage processing device 300A and 300B as respectively illustrated inFIG. 3A and FIG. 3B.

Referring to FIG. 4 in conjunction to FIG. 3A, the receiving circuit 310would receive an original video frame (Step S402), and the maskingcircuit 320 would mask at least one private area in the original videoframe to generate a protected video frame (Step S404). Herein, suchprivate area may be a facial area of a person and may be masked throughany face blurring techniques as known per se. In other words, theidentity of the person appearing in the protected video frame may beprotected and anonymized. Next, the encoding circuit 330 would generatea first encoded frame by encoding the protected video frame (Step S406),and the output circuit 408 would generate at least one output bitstreamfor streaming or storage according to the first encoded frame (StepS408). More details would be provided later. Note that the stepsS402-S406 could also be performed by the processor 350 of the imageprocessing device 300B in FIG. 3B. The descriptions would be omitted forbrevity's sake.

For better comprehension, FIG. 5 illustrates a functional diagram of aproposed method for encoding private data in accordance with one of theexemplary embodiments of the disclosure. The steps of FIG. 5 could beimplemented by the proposed image processing device 300A and 300B asrespectively illustrated in FIG. 3A and FIG. 3B. In the followingdescription, only one frame would be presented for illustrationpurposes.

Referring to FIG. 5 in conjunction to FIG. 3A, the receiving circuit 310would receive an original video frame Fn and duplicate (S510) theoriginal frame Fn to generate a duplicated original video frame Cn.Next, the masking circuit 320 would mask (S520) the duplicated originalvideo frame Cn to generate a protected video frame Cn′.

The encoding circuit 330 would encode (S530) the protected video frameCn′ to generate a reference frame Rn and a first encoded frame Xn. Notethat the protected video frame Cn′ would be encoded with a referenceframe R(n−1) if coded to p-frame. The encoding circuit 330 would alsoencode (S530) the original video frame Cn by using the reference frameRn to generate a second encoded frame Yn. Next, the encrypting circuit335 would encrypt the second encoded frame Yn to generate an encryptedsecond encoded frame Zn using, for example, the AES encryptionalgorithm.

The output circuit 340 would generate at least one output bitstream forstreaming or storage according to the first encoded frame Xn (consideredas a normal bitstream) and the encrypted second encoded frame Zn(considered as an encrypted bitstream). Herein, the output circuit 340would pack (S540) the first encoded frame Xn and the encrypted secondencoded frame Zn into one bitstream or separated bitstreams for storageor streaming. In one exemplary embodiment, the output circuit 340 maypack the first encoded frame Xn into a first output bitstream and packthe encrypted second encoded frame into a second output bitstream. Inanother exemplary embodiment, the output circuit 340 may pack the firstencoded frame Xn and the encrypted second encoded frame Zn into acombined output bitstream.

Note that the flow in FIG. 5 could also be performed by the processor350 of the image processing device 300B in FIG. 3B. The descriptionswould be omitted for brevity's sake.

In terms of video encoding, note that the second encoded frame Yn keepsthe difference between the original frame Fn and the reference frame Rnonly. The bitstream Zn would only contain private data (private area)and would be considered as “a private layer”. The private layer would bepacked in the supplemental enhancement information (SEI) in the networkabstraction layer (NAL) unit. In terms of video decoding and playback,the SEI would be packed with a normal bitstream and would be ignored byNVR while playback and liveview, and NVR would play the private layeronly with an authorized key (i.e. a decryption key).

In detail, FIG. 6A and FIG. 6B illustrate schematic diagrams of proposedimage processing devices in accordance with one of the exemplaryembodiments of the disclosure. Note that both image processing devicesproposed in FIG. 6A and FIG. 6B would be used for decoding private data.All components of the image processing devices and their configurationsare first introduced in FIG. 6A and FIG. 6B. The functionalities of thecomponents are disclosed in more detail in conjunction with FIG. 7.

Referring to FIG. 6A, an image processing device 600A would beimplemented as an integrated circuit (IC) including a receiving circuit610, a decoding circuit 620, and an output circuit 630, where thedecoding circuit 620 is coupled to the receiving circuit 610, and theoutput circuit 630 is coupled to the decoding circuit 620. Note that inone of exemplary embodiments, a decrypting circuit 625 coupled betweenthe decoding circuit 620 and the output circuit 630 may be optionallyincluded in the image processing device 600A.

Referring to FIG. 6B, an image processing device 600B would be anelectronic system or a computer system that includes a processor 650.The processor 650 may be may be one or more of a North Bridge, a SouthBridge, a FPGA, a PLD, an ASIC, other similar devices, or a combinationthereof. The processor may also be a CPU, a programmable general purposeor special purpose microprocessor, a DSP, a GPU, other similar devices,or a combination thereof.

FIG. 7 illustrates a flowchart of a proposed method for decoding privatedata in accordance with one of the exemplary embodiments of thedisclosure. The steps of FIG. 7 could be implemented by the proposedimage processing device 600A and 600B as respectively illustrated inFIG. 6A and FIG. 6B.

Referring to FIG. 7 in conjunction to FIG. 6A, the receiving circuit 610would receive at least one input video bitstream to obtain a firstencoded bitstream and a second encoded bitstream (Step S702). Next, thedecoding circuit 620 would decode the first encoded bitstream togenerate a protected video frame including image data of at least oneprivate area (Step S704), and the output circuit 630 would output theprotected video frame to a display queue such that the at least oneprivate area is displayed (Step S706). More details would be providedlater. Note that the steps S702-S706 could also be performed by theprocessor 650 of the image processing device 600B in FIG. 6B. Thedescriptions would be omitted for brevity's sake.

For better comprehension, FIG. 8A illustrates a functional diagram of aproposed method for decoding private data in accordance with one of theexemplary embodiments of the disclosure. The steps of FIG. 8A could beimplemented by the proposed image processing device 600A and 600B asrespectively illustrated in FIG. 6A and FIG. 6B. In the followingdescription, only one frame would be presented for illustrationpurposes.

Referring to FIG. 8A in conjunction to FIG. 6A, the receiving circuit610 would receive an input bitstream (Xn, Zn) (S810) as packed in (S540)in FIG. 5, where Xn and Zn would be referred to as “a first encodedbitstream” and “a second encoded bitstream” hereafter. Next, decodingcircuit 620 would decode the first encoded bitstream Xn to reconstruct areference frame Rn not having image data of at least one private area(S820). Note that the first bitstream Xn would be decoded with areference frame R(n−1) if coded to p-frame. Next, the decrypting circuit625 would determine whether the second encoded bitstream Zn isauthorized to be decoded (i.e. whether an authorized key is available)(S830).

If the second encoded bitstream Zn is not authorized to be decoded, theoutput circuit 630 would send the reference frame Rn to a display queue(S840). Herein, only the first encoded bitstream Xn is decoded, and onlythe reference frame Rn is output to the display queue. The secondencoded bitstream Zn is not decoded, and the protected video frame Cn′is not output to the display queue. Since only the reference frame Rn isdisplayed with the private area being blurred.

On the other hand, if the second encoded bitstream Zn is authorized tobe decoded, the decrypting circuit 625 would decrypt the second encodedbitstream Zn to a second encoded frame Yn (S850) and decode the secondencoded frame Yn with the reference frame Rn to reconstruct a protectedvideo frame Cn′ (S860), and the output circuit 630 would send theprotected video frame to the display queue (S870). Herein, both thefirst encoded bitstream Xn and the second encoded bitstream Zn aredecoded to generate the reference frame Rn and the protected video frameCn′ that are output to the display queue. Therefore, a whole image (i.e.an original frame) would be displayed without the private area beingblurred. Once the input bitstream (Xn, Zn) has been processed, the flowmoves to S810 to process a subsequent bitstream (X(n+1), Z(n+1)).

Note that the flow in FIG. 8A could also be performed by the processor650 of the image processing device 600B in FIG. 6B. The descriptionswould be omitted for brevity's sake.

FIG. 8B illustrates a schematic diagram of private data and protecteddata for playback in accordance with one of exemplary embodiments of thedisclosure. During video playback, if the authorized key does not exist,only the protected data 81, 83, 85, 87 would be displayed. If theauthorized key exists, the protected data 81, 83, 85, 87 would bealternately combined with the protected data 82, 84, 86, 88, and thecombination of the protected data and the private data 81-88 would bedisplayed.

Note that in the flows in FIG. 6 and FIG. 8A, the private data is ableto be secured at a data level by using a single video stream with aprotected private layer. Non-private video would be decoded in NVRwithout certification, and the private layer requires an authorized keyfor decoding with instant authorization and expiration. For example, theauthorized key may be different for each camera, each zone, each timeinterval, and so forth. Moreover, reduced spaces (approximately only upto 1.2 times of memory spaces) are required for storage and streamingfor transmission.

In view of the aforementioned descriptions, the proposed methods and theimage processing devices would be able to provide video transmission ina secure and efficient fashion.

No element, act, or instruction used in the detailed description ofdisclosed embodiments of the present application should be construed asabsolutely critical or essential to the present disclosure unlessexplicitly described as such. Also, as used herein, each of theindefinite articles “a” and “an” could include more than one item. Ifonly one item is intended, the terms “a single” or similar languageswould be used. Furthermore, the terms “any of” followed by a listing ofa plurality of items and/or a plurality of categories of items, as usedherein, are intended to include “any of”, “any combination of”, “anymultiple of”, and/or “any combination of multiples of the items and/orthe categories of items, individually or in conjunction with other itemsand/or other categories of items. Further, as used herein, the term“set” is intended to include any number of items, including zero.Further, as used herein, the term “number” is intended to include anynumber, including zero.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of thedisclosed embodiments without departing from the scope or spirit of thedisclosure. In view of the foregoing, it is intended that the disclosurecover modifications and variations of this disclosure provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. A method for encoding private data comprising:receiving an original video frame; masking at least one private area inthe original video frame to generate a protected video frame; performingan encoding operation on the protected video frame to generate a firstencoded frame and a specific reference frame; generating at least oneoutput bitstream for streaming or storage according to the first encodedframe; and using the specific reference frame generated from theprotected video frame to encode the original video frame.
 2. The methodof claim 1 further comprising: generating a second encoded frame byencoding the original video frame, and wherein the step of generatingthe at least one output bitstream for streaming or storage according tothe first encoded frame comprises: generating the at least one outputbitstream for streaming or storage according to the first encoded frameand the second encoded frame.
 3. The method of claim 2 furthercomprising: encrypting the second encoded frame to generate an encryptedsecond encoded frame, wherein the step of generating the at least oneoutput bitstream for streaming or storage according to the first encodedframe comprises: generating the at least one output bitstream forstreaming or storage according to the first encoded frame and theencrypted second encoded frame.
 4. The method of claim 3, wherein the atleast one output bitstream comprises a first output bitstream and asecond output bitstream, and wherein the step of generating the at leastone output bitstream for streaming or storage according to the firstencoded frame and the second encoded frame comprises: packing the firstencoded frame into the first output bitstream; and packing the encryptedsecond encoded frame into the second output bitstream.
 5. The method ofclaim 3, wherein the at least one output bitstream comprises a combinedoutput bitstream, and wherein the step of generating the at least oneoutput bitstream for streaming or storage according to the first encodedframe and the second encoded frame comprises: packing the first encodedframe and the encrypted second encoded frame into the combined outputbitstream.
 6. The method of claim 1 further comprising: duplicating theoriginal video frame to generate a duplicated original video frame; andperforming masking on the duplicated original video frame.
 7. An imageprocessing device comprising: a receiving circuit, configured to receivean original video frame; a masking circuit, configured to mask at leastone private area in the original video frame to generate a protectedvideo frame; an encoding circuit, configured to perform an encodingoperation on the protected video frame to generate a first encoded frameand a specific reference frame, wherein the encoding circuit is furtherconfigured to encode the original video frame by using the specificreference frame generated from the protected video frame; and an outputcircuit, configured to generate at least one output bitstream forstreaming or storage according to the first encoded frame.
 8. The imageprocessing device of claim 7, wherein the encoding circuit is furtherconfigured to generate a second encoded frame by encoding the originalvideo frame, and wherein the output circuit is configured to generatethe at least one output bitstream for streaming or storage according tothe first encoded frame and the second encoded frame.
 9. The imageprocessing device of claim 8 further comprising: an encrypting circuit,configured to encrypt the second encoded frame to generate an encryptedsecond encoded frame, wherein the output circuit is further configuredto generate the at least one output bitstream for streaming or storageaccording to the first encoded frame and the encrypted second encodedframe.
 10. The image processing device of claim 9, wherein the at leastone output bitstream comprises a first output bitstream and a secondoutput bitstream, and wherein the output circuit is configured togenerate the at least one output bitstream for streaming or storageaccording to the first encoded frame and the second encoded frame bypacking the first encoded frame into the first output bitstream andpacking the encrypted second encoded frame into the second outputbitstream.
 11. The image processing device of claim 9, wherein the atleast one output bitstream comprises a combined output bitstream, andwherein the output circuit is configured to generate the at least oneoutput bitstream for streaming or storage according to the first encodedframe and the second encoded frame by packing the first encoded frameand the encrypted second encoded frame into the combined outputbitstream.
 12. The image processing circuit of claim 7, wherein thereceiving circuit is further configured to duplicate the original videoframe to generate a duplicated original video frame, and wherein themasking circuit is configured to perform masking on the duplicatedoriginal video frame.
 13. An image processing device comprising: aprocessor, configured to: receive an original video frame; mask at leastone private area in the original video frame to generate a protectedvideo frame; perform an encoding operation on the protected video frameto generate a first encoded frame and a specific reference frame;generate at least one output bitstream for streaming or storageaccording to the first encoded frame; and using the specific referenceframe generated from the protected video frame to encode the originalvideo frame.
 14. A method for decoding private data comprising:receiving a first encoded bitstream and receiving a second encodedbitstream different from the first encoded bitstream; decoding the firstencoded bitstream to generate a specific reference frame comprising ablurred image data and generate a protected video frame comprising imagedata associated with at least one private area, wherein the blurredimage data generated from the first encoded bitstream serves to decodethe second encoded bitstream different from the first encoded bitstream;and outputting the protected video frame to a display queue such thatthe at least one private area is displayed.
 15. The method of claim 14,further comprising: outputting the specific reference frame to thedisplay queue.
 16. The method of claim 15 further comprising: decryptingthe second encoded bitstream when a key is authorized before the secondencoded bitstream is decoded.
 17. The method of claim 16, wherein boththe first encoded bitstream and the second bitstream are decoded togenerate both the specific reference frame and the protected video framewhich are output to the display queue when the key is authorized suchthat a whole image is displayed without the at least one private areabeing blurred.
 18. The method of claim 16 further comprising: notdecrypting the second encoded bitstream when the key is not authorized.19. The method of claim 18, wherein when the key is not authorized, onlythe first encoded bitstream is decoded and only the specific referenceframe is output to the display queue and the second encoded bitstream isnot decoded and the protected video frame is not output to the displayqueue, such that the at least one private area is blurred in response toonly the specific reference frame is being displayed.
 20. An imageprocessing device comprising: a receiving circuit, configured to receivea first encoded bitstream and receive a second encoded bitstreamdifferent from the first encoded bitstream; a decoding circuit,configured to decode the first encoded bitstream to generate a specificreference frame comprising a blurred image data and generate a protectedvideo frame comprising image data associated with at least one privatearea, wherein the blurred image data generated from the first encodedbitstream serves to decode the second encoded bitstream different fromthe first encoded bitstream; and an output circuit configured to outputthe protected video frame to a display queue such that the at least oneprivate area is displayed.
 21. The image processing device of claim 20,wherein the output circuit is further configured to output the specificreference frame to the display queue.
 22. The image processing device ofclaim 21 further comprising: a decrypting circuit, configured to decryptthe second encoded bitstream when a key is authorized before the secondencoded bitstream is decoded.
 23. The image processing device of claim21, wherein the decoding circuit is configured to decode both the firstencoded bitstream and the second bitstream to generate both the specificreference frame and the protected video frame, and wherein the outputcircuit is configured to output both the specific reference frame andthe protected video frame to the display queue when the key isauthorized such that a whole image is displayed without the at least oneprivate area being blurred.
 24. The image processing device of claim 22,wherein the decrypting circuit is not configured to decrypt the secondencoded bitstream when the key is not authorized.
 25. The imageprocessing device of claim 24, wherein the decoding circuit isconfigured to decode only the first encoded bitstream when the key isnot authorized, and wherein the output circuit is configured to outputonly the specific reference frame to the display queue when the key isnot authorized, such that the at least one private area is blurred inresponse to only the specific reference frame is being displayed.
 26. Animage processing device comprising: a processor, configured to: receivea first encoded bitstream and receive a second encoded bitstreamdifferent from the first encoded bitstream; decode the first encodedbitstream to generate a specific reference frame comprising a blurredimage data and generate a protected video frame comprising image dataassociated with at least one private area, wherein the blurred imagedata generated from the first encoded bitstream serves to decode thesecond encoded bitstream different from the first encoded bitstream; andoutput the protected video frame to a display queue such that the atleast one private area is displayed.